1. Field of the Invention
The invention relates to a signalling post adapted to be mounted on a flexible base. While the post per se remains rigid when hit laterally and in particular by a vehicle, it is expected to tilt due to the flexibility of the base on which it is preferably mounted.
The post consists of a combination of an outer tubular member made of an expensive material and an inner sleeve made of a cheap material. The thickness of the outer tubular member can, accordingly, be of reduced thickness to maintain the required rigidity by the introduction of the inner sleeve which reinforces the rigidity of the outer tubular member.
It is an object of the invention to make use of the two superposed inner sleeve and tubular member for displaying a reflective material between the inner sleeve and the tubular member. Accordingly, the tubular member protects the reflecting material from objects hitting the post, from weather conditions and generally from any external destructive conditions.
The material selected for making the outer tubular member is polycarbonate. Polycarbonate, if used alone, is transparent and practically invisible as a signalling post. Colored polycarbonate is generally not available and is expensive to produce. The inner sleeve, which is opaque, is easily available in a large variety of colors. It is according to an additional object of the invention to produce a colored cheaper post.
2. Prior Art
U.S. Pat. No. 4,343,567 to R. B. Sarver is directed to a self-erecting roadway marking post which is made of two concentrically superposed tubes. The outer tube is made polyvinyl chloride which is relatively rigid but such a material is adapted to flex under relatively small lateral blows. The inner tube is made of a flexible material such as low density polyethylene. The post, according to this invention, is particularly designed to be easily and quickly replaced because it is made of a relatively fragile outer tube which has no significant memory.
Furthermore, Sarver wraps a light reflecting sheet around the outer tube at the upper end thereof. In a second embodiment, the reflective surface is positioned inside the marking tube which is provided with an opening so that the reflective surface can be made visible. Such an opening is necessitated by the fact that the marking tube is not transparent. In fact, both the inner and the outer tubes are opaque considering that the polyvinyl chloride and polyethylene are not transparent. Furthermore, the inner tube is not contemplated to reach the upper end of the outer tube and consequently, the inner tube has no use in the installation of the reflective surface inside the outer tube.